Long-term data storage has long been accomplished on such media as magnetic tape and rigid magnetic discs, as well as punched paper cards and tape. More recently, the advent of flexible disc recording technologies have shown the advantages of the inexpensive limp or "floppy" flexible discs, typically made by coating the opposite sides of a thin highly flexible sheet of polymeric or other plastic film with magnetic oxide, with the coated disc being only on the order of 3 to 4 mils thick. This limply flexible disc is permanently enclosed within a close-fitting sleeve-like protective outer envelope, in which it may be rotated while the envelope is held in position. The envelope has an enlarged central opening for access to the center of the disc, and also has a radial slot opening, by which a magnetic head may access the face of the disc while the same is rotated. For example, the disc structure may be substantially as shown in U.S. Pat. No. 3,668,658 entitled MAGNETIC RECORD DISC COVER issued June 6, 1972 to Ralph Flores, et al., and one form of recorder/reproducer device for such a device is shown in U.S. Pat. No. 3,678,481 entitled DATA STORAGE APPARATUS EMPLOYING A SINGLE MAGNETIC DISC issued July 18, 1972 to Warren L. Daiziel, et al.
An improved recorder/reproducer apparatus for flexible disc recording, having greatly increased operational flexibility, greatly increased recording capacity, and considerably different structural characteristics from recorders used heretofore is shown in commonly assigned copending application Ser. No. 418,299 filed Nov. 23, 1973 entitled FLEXIBLE DISC RECORDER CONSTRUCTION and Ser. No. 510,471 filed Sept. 30, 1974 entitled METHOD AND APPARATUS FOR MOUNTING & POSITIONING MAGNETIC RECORDING HEADS.
The apparatus disclosed in the above-mentioned commonly assigned copending applications has a pair of pivotally mounted door-like structures adapted to receive the flexible disc elements, and to record on either or both sides of either or both such discs, as may be required. The apparatus includes at least two magnetic heads, and means mounting the same for articulated movement toward and away from their respective recording discs, as well as means mounting the heads for translational movement across the face of the discs while the same are rotated. A common drive means is provided by which both recording discs may be rotatably driven, as well as a common translational drive for the magnetic heads.